Author
Yi Yang
Bio: Yi Yang is an academic researcher from Novartis. The author has contributed to research in topics: Medicine & Genome editing. The author has an hindex of 14, co-authored 20 publications receiving 1050 citations.
Topics: Medicine, Genome editing, Embryonic stem cell, Biology, CRISPR
Papers
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TL;DR: ObLiGaRe is described, a new method for site-specific gene insertions that uses the efficient NHEJ pathway and acts independently of HR, and has enabled us to insert a 15-kb inducible gene expression cassette at a defined locus in human cell lines.
Abstract: Custom-designed nucleases (CDNs) greatly facilitate genetic engineering by generating a targeted DNA double-strand break (DSB) in the genome. Once a DSB is created, specific modifications can be introduced around the breakage site during its repair by two major DNA damage repair (DDR) mechanisms: the dominant but error-prone nonhomologous end joining (NHEJ) pathway, and the less-frequent but precise homologous recombination (HR) pathway. Here we describe ObLiGaRe, a new method for site-specific gene insertions that uses the efficient NHEJ pathway and acts independently of HR. This method is applicable with both zinc finger nucleases (ZFNs) and Tale nucleases (TALENs), and has enabled us to insert a 15-kb inducible gene expression cassette at a defined locus in human cell lines. In addition, our experiments have revealed the previously underestimated error-free nature of NHEJ and provided new tools to further characterize this pathway under physiological and pathological conditions.
312 citations
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TL;DR: The results indicate that the RSPO–LGR4/5–ZNRF3/RNF43 module controls metabolic liver zonation and is a hepatic growth/size rheostat during development, homeostasis and regeneration.
Abstract: LGR4/5 receptors and their cognate RSPO ligands potentiate Wnt/β-catenin signalling and promote proliferation and tissue homeostasis in epithelial stem cell compartments. In the liver, metabolic zonation requires a Wnt/β-catenin signalling gradient, but the instructive mechanism controlling its spatiotemporal regulation is not known. We have now identified the RSPO-LGR4/5-ZNRF3/RNF43 module as a master regulator of Wnt/β-catenin-mediated metabolic liver zonation. Liver-specific LGR4/5 loss of function (LOF) or RSPO blockade disrupted hepatic Wnt/β-catenin signalling and zonation. Conversely, pathway activation in ZNRF3/RNF43 LOF mice or with recombinant RSPO1 protein expanded the hepatic Wnt/β-catenin signalling gradient in a reversible and LGR4/5-dependent manner. Recombinant RSPO1 protein increased liver size and improved liver regeneration, whereas LGR4/5 LOF caused the opposite effects, resulting in hypoplastic livers. Furthermore, we show that LGR4(+) hepatocytes throughout the lobule contribute to liver homeostasis without zonal dominance. Taken together, our results indicate that the RSPO-LGR4/5-ZNRF3/RNF43 module controls metabolic liver zonation and is a hepatic growth/size rheostat during development, homeostasis and regeneration.
240 citations
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TL;DR: It is found that BECs lack and do not require LGR4/5-mediated WNT/β-catenin signaling during a DR, whereas YAP and mTORC1 signaling are required for this process.
149 citations
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TL;DR: DVL is revealed as a dual function adaptor to recruit negative regulators ZNRF3/RNF43 to Wnt receptors to ensure proper control of pathway activity.
122 citations
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TL;DR: Findings show hepatocytes throughout the liver can upregulate AXIN2 and LGR5 after injury and contribute to liver regeneration on demand, without zonal dominance by a putative pericentral stem cell population.
109 citations
Cited by
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TL;DR: In this paper, the authors characterized Cpf1, a putative class 2 CRISPR effector, which is a single RNA-guided endonuclease lacking tracrRNA and utilizes a T-rich protospacer-adjacent motif.
3,436 citations
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TL;DR: A review of achievements made possible by site-specific nuclease technologies and applications of these reagents for genetic analysis and manipulation, including the therapeutic potential of ZFNs and TALENs, and future prospects for the field are discussed.
3,235 citations
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TL;DR: In this paper, an approach that combines a Cas9 nickase mutant with paired guide RNAs to introduce targeted double-strand breaks is described. But the approach is limited to mouse zygotes.
3,026 citations
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TL;DR: The core Wnt/β-catenin signaling pathway is described, how it controls stem cells, and contributes to disease, and strategies for Wnt-based therapies are discussed.
2,663 citations
01 Sep 2013
TL;DR: It is demonstrated that using paired nicking can reduce off-target activity by 50- to 1,500-fold in cell lines and to facilitate gene knockout in mouse zygotes without sacrificing on-target cleavage efficiency.
Abstract: Targeted genome editing technologies have enabled a broad range of research and medical applications. The Cas9 nuclease from the microbial CRISPR-Cas system is targeted to specific genomic loci by a 20 nt guide sequence, which can tolerate certain mismatches to the DNA target and thereby promote undesired off-target mutagenesis. Here, we describe an approach that combines a Cas9 nickase mutant with paired guide RNAs to introduce targeted double-strand breaks. Because individual nicks in the genome are repaired with high fidelity, simultaneous nicking via appropriately offset guide RNAs is required for double-stranded breaks and extends the number of specifically recognized bases for target cleavage. We demonstrate that using paired nicking can reduce off-target activity by 50- to 1,500-fold in cell lines and to facilitate gene knockout in mouse zygotes without sacrificing on-target cleavage efficiency. This versatile strategy enables a wide variety of genome editing applications that require high specificity.
1,947 citations